The U.S. government has sued a specific individual in a major case alleging fraudulent subprime mortgage sales in the lead up to the financial crisis.

Rebecca Mairone, formerly a top official at Countrywide Financial, has been named in an amended complaint filed earlier this month by Preet Bharara, the U.S. Attorney for the Southern District of New York, against Countrywide and its parent Bank of America. The suit alleges that Mairone, as chief operating officer for Countrywide's Full Spectrum Lending division in 2007, set up a program dubbed the "High Speed Swim Lane," or "HSSL," or "Hustle," to speed up the origination of mortgage loans, including increasingly shady subprime loans. The government claims the alleged Hustle ultimately cost its sponsored entities Fannie Mae and Freddie Mac more than $1 billion in losses.

Mairone now works for JPMorgan Chase and is in charge of that bank's efforts to compensate victims of foreclosure fraud, ProPublica recently reported.

JPMorgan referred questions to Mairone's attorney, Marc Mukasey of the law firm Bracewell & Giuliani. In an emailed statement, Mukasey said his client had done no wrong.

"Rebecca Mairone has always been a loud voice for ethics and integrity in the mortgage business and she will be vindicated because she never did anything improper," Mukasey wrote. "The Government has trumped up a meritless case against Countrywide and Bank of America and has chosen to lay false blame at the feet of Rebecca, a single mother who is a champion of diversity and women's leadership and who has personally helped thousands of distressed homeowners, veterans and working people to avoid foreclosure and stay in their homes."

Bank of America echoed that sentiment in a statement.

"Bank of America asked that the court dismiss the U.S. Attorney's complaint for lack of merit, so they've revised their legal theories," said Bank of America spokesman Lawrence Grayson. "We believe they're equally unfounded and that neither Bank of America nor Countrywide defrauded Fannie Mae or Freddie Mac."

Countrywide, once one of the largest mortgage lenders in the U.S., nearly collapsed in 2008 and was acquired on the cheap by Bank of America that summer. The deal continues to haunt Bank of America with mortgage losses and legal headaches.

According to the complaint, the Hustle program began after the subprime mortgage market had started to collapse, and continued through 2009, long after Countrywide was rescued by Bank of America. The government has alleged that although the Hustle was originally designed for prime loans, Mairone pushed it to include "dirty prime" and subprime loans.

Bharara accuses Mairone and Countrywide of using the program, the motto of which was "Loans Move Forward, Never Backward," to funnel toxic loans straight to government-sponsored entities Fannie Mae and Freddie Mac, "with the knowing misrepresentation that they were investment-quality loans that complied with GSE requirements."

Mairone and other Countrywide officials ignored warnings from other bank employees that the Hustle program created "a disastrous layering of risk" of churning out fraudulent loans, according to the complaint. The lawsuit also alleges that Mairone told grumbling employees to "get with the program" and even reduced the responsibilities of those who made too much noise about it.